As doctor's say children will have there food when ever they feel like and whatever they feel like. but we people being mother's are always worried. In this case you can try mixing some fruits with milk to give it a flavour so the he enjoys it just try to keep the texture of the food like paste like. You can even try giving ragi with little milk and jaggery. it's also a healthy option for your child, other than these u can also go for dual ka paani. Try to indulge your child in some interesting activity during feeding. I m sure he is gonna eat properly.